1. Field of the Invention
The present invention relates to swimming goggles, and particularly to swimming goggles with an adjustable head strap.
2. Related Art
Conventional swimming goggles have a head strap adjustable by buckles. The buckle is generally shaped with a couple of loops adjoining to each other. The two free ends of the head strap respectively extend through the loops and are overlapped. As changing length of the head strap, friction produced by the overlapped part of the head strap blocks movement, making adjustment cumbersome.
Another fashion of conventional buckles are respectively disposed on left sides and right sides of the eyeglasses frame. Each conventional buckle forms a biasing arm, which biases against denticulate grooves of the head strap, thus the head strap is allowed to be adjusted in a single direction only (namely shortening length of the head strap). To loosen the head strap, the biasing arm is disengaged from the denticulate grooves. However, the conventional buckles are strictly required in manufacture, and therefore lead to high cost. So, it is desired to make buckles of swimming goggles be easily used and manufactured.
Furthermore, swimming goggles with a left frame, a right frame and a connecting portion integrated together, demand material which enables lenses retained in the left frame and the right frame. The material should not be so soft that can not fix the lenses and resist water pressure. The material is therefore limited to given rigidness, and a pad formed on the left frame and the right frame can not be soft sufficient to touch a user's face comfortably when wearing. Additionally, because the integrated swimming goggles opt for material with given rigidness, the connecting portion between the left frame and the right frame is too stiffened to suit for users with different face profiles, and the left frame and the right frame can not fit close to the user's face, thus taking risk of water leakage.